Fix compilation bug for non hdfs build

Summary:
the lzo code introduced a bug

Test Plan:
Testsuite

DiffCamp Revision: 113044
Reviewed By: pkhemani
CC: agiardullo, pkhemani, scribe-dev@lists
Revert Plan:
OK

git-svn-id: svn+ssh://tubbs/svnapps/fbomb/trunk/fbcode/scribe@27432 2248de34-8caa-4a3c-bc55-5e52d9d7b73a

src/HdfsFile.h

@@ -75,6 +75,7 @@ class HdfsFile : public FileInterface {
   void close()    {};
   bool write(const std::string& data) { return false; };
   void flush()    {};
+  void sync()     {};
   unsigned long fileSize() { return 0; };
   bool readNext(std::string& _return) { return false; };
   void deleteFile() {};